The rationale for this study design is based on the fact that the maximum tolerated dose (MTD) of single-agent ofatumumab and bendamustine have been previously determined. The choice of the doses for the combination is based on the investigators unpublished clinical experience, as well as inferred from extensive experimental data on the use of other monoclonal antibodies in combination chemotherapy in lymphoma patients. The starting dose of the 2 main component drugs is the MTD of each drug as single agent.